The proposals were considered by UCU’s higher education committee and branch representatives on Tuesday, but rejected, the union said.

Lectures and classes have been disrupted at more than 60 universities by 14 days of strikes across four weeks, due to end with a five-day walkout until Friday.

UCU said “detailed preparations” will be made for strikes “over the assessment and exam period”.

The union’s general secretary Sally Hunt said: “Branches made it clear today that they wanted to reject the proposal.

“UCU’s greatest strength is that we are run by and for our members and it is right that members always have the final say.

“The strike action for this week remains on and we will now make detailed preparations for strikes over the assessment and exam period.

“We want urgent talks with the universities’ representatives to try and find a way to get this dispute resolved.”

Staff have been striking in protest at changes to the Universities Superannuation Scheme (USS).

The row centres on proposals that would change the USS from a “defined benefit” scheme, which gives workers a guaranteed income in their retirement, to a purely “defined contribution” scheme, in which pensions are subject to fluctuations in the stock market.

UCU had argued that the reforms, which UUK maintained were necessary, would leave a typical lecturer almost £10,000 a year worse off in retirement.

Talks had been mediated by the conciliation service Acas.

UUK said it was now consulting with USS employers about a “revised mandate” ahead of a scheduled joint negotiating committee meeting which will be attended by UUK and UCU representatives on Wednesday.

The committee, which decided upon the benefit changes in January, has an independent chair who can choose to cast a deciding vote if agreement between both parties cannot be reached, according to UUK.

A UUK spokesman said: “It is hugely disappointing that students’ education will be further disrupted through continued strike action.

“We have engaged extensively with UCU negotiators to find a mutually acceptable way forward.

“The jointly developed proposal on the table, agreed at Acas, addresses the priorities that UCU set out.

“We have listened to the concerns of university staff and offered to increase employer contributions to ensure that all members would receive meaningful defined benefits.

“We recognised concerns raised about the valuation and have agreed to convene an independent expert valuation group.

“Our hope is that UCU can find a way to continue to engage constructively, in the interests of students and those staff who are keen to return to work.”